Transmission gearing



Feb. 28, 1950 w. L. SHEPPARD 2,498,828

TRANSMISSION GEARING Filed July 1, 1945 Patented Feb. 28, 1950 UNITED STATES PATENT OFFICE William L. Sheppard, RoyalOak, Mich, assignor to Borg-Warner Corporation, Chicago, 111;, a corporation of Illinois Application July 1 1943, Serial No. 493501 2.

The present invention relates. to transmission gearing, andv it has for its principal object to provide a desired ratio of reduction ina gearing. that is adapted to be employedfor driving and driven shafts having normally vertical, preferably alined axes.

Also, it is anobjectof this invention to provide instrumentalities in. a transmission. gearing whereby the rotational. movement. of the axially alined. drive and driven shafts is adapted to be eifectively transmitted. to a supplementary or auxiliary shaft that maybe disposed at an angle to said shafts. A transmission. gearing. structure such as above suggested is especially applicable for use in a helicopter for actuating both the sustaining rotor andthe tail rotor or stabilizing. propeller thereof.

It. is one of the principal. objects: of this invention. to simplify the construction of a-transmission gearing of. the character contemplated herein,.and to improve the efiiciency and operation of such gearing.

Another object is to provide a gearing of the. character above-mentioned wherein the. power take-off of the lateral or. auxiliary shaft is made direct from a. portion. of. the carrier for a. plan.- etary gear train. assembly which comprises. a part of. the transmission structure; A. further object resides in the. particular disposition. of the auxiliary shaft gears so that they are in spacedrelation. to the planetary gear train. assembly from.

which the aforesaid auxiliary shaft gears derive their motion,. thereby permitting the use ofthe. best gear ratio without unduly increasing the size and weight of the transmission.

It is a. still further object. to provide. an eticient lubrication system for the various instrumentalities which. surround. the vertically disposed. shafts,. the system. utilizing a minimum of drilled. passageway in the. transmission housing, and. in connection therewith to provide a pump to force the. lubricant. to different locations. pump is a. concentrically disposed structure surrounding the. drive shafaand it. ispre-ferably immersed in the oil. in. a. sump or oil-reservoir. near the lower end of the housing.

In the transmission gearing structure which is contemplated herein,.the end thrust which. is developed in the gearing. is adapted to balance at least a portion. of the upward. thrust. of the driven. shaft, which will. result in. smaller bearing. loads and lesswear on the moving parts.

Additional objects, aims,. and. advantages. of. the present invention will be. apparent to] persons skilled in the art after the construction and op- The I 2 eration of the transmission gearingis understood from the descriptionwhich follows.

It is preferred to accomplish the numerous obv jects of this invention and. to practice the same r the. drawing. embodies. a. typical arrangement of the i'nstrumentalities for. carrying out this in.- vention,. and it. preferably embodies a vertical drive-shaft. 5' thatis axially bored at 5a and has an annular flange 6,. secured to its lower end by means. of the. spline 7,. through the medium of which. the drive-shaft derives itsrotative motion fromthe prime mover (not shown) of the helicopter. The motor may be operatively connected to said flange 6 bymeans of a. suitable clutch. (not. shown). Above the drive-shaft 5 there is a driven-shaft 8 that is axially bored at 8a and is disposed with its axis in vertical alinement with. said drive-shaft. This driven-shaft 8 extends above the body of the helicopter and isadapted to actuate the sustaining rotor of the aircraft.

I'nterposed between and. operatively connecting. the alined driving. and. driven shafts there is a two-stage reduction gearing which provides a. high ratio reduction drive connection between.

saidshafts. and it preferably comprisesupper and lower epicyclic or planetary gear train assemblies of. the helical type which are identified generally as-il and i0 respectively. The auxiliary shaft II for the tail rotor or stabilizer propeller is shown.

with its axis inclined downwardly from the axes of the main shafts 5 and 8, and it has its power take-off from the lower epicyclic or planetary gear train assembly 10 from which it is suitably spaced.v

The transmission gearing is. enclosed in a twopart housing, the upper member l2 of which has a. generally conical shape and is provided with an annular basal flange l3 having a plurality of bored. lugs to-receive clampingbolts Mwhich pass.

throughthe upper. annular flange H: of the other member [6. of. the. housing. An oil sump I1 is formed. inthe bottom of the housing. member 16 wherein there is a. cylindrical filter l8, and there is apassageway Heading, from the filter chamber to a suitable pump structure 20 that is of annular shape and concentrically surrounds the lower or ments being adapted to be releasably connected drive-shaft 5 within the housing. by a plurality of rollers 41 that provide the opera- The upper member I2 of the housing is suptive elements of said clutch. These clutch rollers ported on the driven shaft 8 through the in- 4'! are maintained in position by upper and lower strumentality of the large double ball-bearing 5 portions 48 and 49, respectively, of a roller cage 2|, the inner raceway of which bears against a 49a. The one-way or freewheeling clutch is collar 22 threaded onto the adjacent portion of adapted to operatively connect the drive shaft 5 the driven shaft 8, and the outer raceway of this to the sun gear 43 of the lower planetary gear ball-bearing engages a shoulder 23 in the upper train assembly ill to rotate said sun gear 43 with,

portion of the housing member. An annular and at the same speed as, the drive shaft 5 of the disc 24, which is engaged with the lower edge transmission.

of the outer raceway, holds the latter in posi- The upper portion of the sun gear 43 above tion by means of clamping bolts 25 which pass its hub is cupped to provide a shoulder 55 against through the housing and disc to draw these which a retaining washer 5! is seated, the said parts together and force the outer raceway washer being restrained against upward displaceagainst shoulder 23. The drive-shaft 5 is jourment by a snap ring 5la fitted into an annular naled in a large ball-bearing 26 which has its groove 5H) in the adjacent face of the driven inner raceway resting upon the upper end of the shaft 8, and rotation of said washer is prevented hub 21 of the coupling flange 5, the said flange by a stop pin 52 projecting from the shaft into being held fast on the drive-shaft by a nut 28 a transverse slot in the inner face of the washer. screwed onto the threaded reduced lower end 29 The structure which has just been described is of said shaft. The outer raceway of the adapted to assist in rendering the end thrust ball-bearing '26 has its lower edge engaged with produced by the helical gears self-contained in a flanged retainer ring 30 which is secured to the the driven shaft 8.

under side of the housing member !6 by bolts The gear train elements of the lower planetary 3|, and the upper edge of said raceway engages assembly it are supported by a hollow carrier 53 a flanged washer 32 that is interposed between that has an upwardly disposed hub 54 surrounding it and the adjacent portion of the oil pump 20. the driven shaft 8 above the carrier 53, said hub The ball bearing 26, the pump 25, and the interbeing journaled on said shaft in bushings 55 to mediate flanged washer 32, are disposed in superpermit it to rotate independently thereof. The posed relation to each other in a collar 33 havlower portion of hub 54 rests upon a bushing inlng a shouldered or stepped bore to seat these terposed between it and a stationary washer 51 elements, and the narrowest portion of this bore, surrounding the driven shaft and supported upon which is engaged with the drive-shaft 5, has an the snap ring 5ia. This arrangement provides annular channel 34 communicating with the 35 the upper support and bearing for the lower pump 20. The adjacent portion of the drivecarrier 53.

shaft has a lateral passage 35 whereby the lubri- The lower wall of the carrier 53 is provided eating fluid from the pump is discharged into with a shoulder 58 on which are formed downthe bore 5a of the drive-shaft for distribution wardly projecting teeth 5511 that interengage with throughout the parts of the transmission. A in corresponding teeth 59 on the inner surface of a radial passage 36 in the collar 33 establishes cylindrical hollow sleeve 60. The top of this communication between the pump and passagesleeve is centered on shoulder 58 of carrier 53 way l9 from the filter chamber in the oil-sump and its lower portion surrounds and is journaled or reservoir, and an annular flange 31 on the against the annular stub 4| of the lower housing lower portion of the collar 33, which is clamped member H5. The lower end of this sleeve is between the lower end of the housing member provided with a bevel gear 6! that is rotatably l6 and the retainer ring 30, maintains the collar upported by washers 62 on an annular bearing 33 in position. surface 63 alongside and surrounding the stub 4!. Above the collar 33, the drive shaft 5 has a As will be seen at the right side of the drawportion of increased diameter as at 33 to receive 50 ing, the beveled gear 6| provides the power takeand pilot the lower end of the driven shaft 3 Oil for the auxiliary shaft I! through the instruwhich has a shoulder 39 above its piloted portion, mentality of a beveled gear 54 that is suitably and the upper end of the drive shaft terminates secured to the adjacent end of said shaft. The in an outwardly and upwardly flared bell 40. auxiliary shaft structure is rotatably journaled The central lower portion of the housing member in roller bearings 65 in the adjacent end of a 16 is provided with an annular upstanding hollow hollow casing 66 that has an annular flange 51 stub 4| concentric to the drive shaft 5 and spaced at its upper end whereby said end may be infrom said shaft alongside the widened portion 38 serted in an opening in the housing member I6 thereof below the bell 44, and a roller bearing 42 and anchored to the latter by bolts 68 passed is interposed between said stub 4i and the drive through the flange and screwed into the wall of shaft 5 for journaling the latter. the housing. The beveled gear 64 is thus con- The sun-gear 43 of the lower planetary gear veniently located between the carrier 53 and train assembly In is provided with an elongated bevel gear 5! with the result that the desired hub 44 surrounding the adjacent portion of ratio between the speeds of shafts 5 and H can driven shaft 8 upon which it is journaled to perbe readily attained without the use of dispropormit it to rotate independently thereof, and said tionate gears and an undesirably large housing, hub 44 extends down into the bell 4|] of the and with the desired angularity between shafts drive shaft far enough to permit its lower end to 5 and II. rest upon a washer 45 that is interposed between The lower planetary gear train, which includes it and the flat lateral face 46 of said bell, thereb 70 the sun gear 43, embodies a wide ring gear 69 providing support for said sun gear 43. The and a plurality of planet gears ill that are jourconcentrically disposed confronting faces of the naled on hollow trunnions ll mounted in the top drive shaft bell 46 and the sun gear hub 44 comand bottom walls of the carrier 53. The trunprise the opposing or wedging elements of a onenions are of substantial diameters and are seway or freewheeling clutch device, the said elecured in the carrier by pins 12, suitable bearing bushings. and; washerbeing, interposed between saidgears-,. their respective trunnions, andthe adjacent surfaces; or the: carrienwalls.

The beforeementioned hub 54 oil thalower carrier 53: projects. into; the. upper carrieris withv its upper end engaged with; a washer M that. is interposed between said end. and a. shoulder i=5 onthe driven shaft. 8-,, and said carrier. 1-31 is pro.- vided with an upstanding tapered hub. 14' that engages thelower portionxof the large double ball-bearing 2|.

The upper gear-train. comprises a sun gear 1'! preferably formed. on the. lower carrier hub. 54, a plurality of planet gears 18 .rotatabl'y mounted on trunnions l9, and the wide ring gear 69. This ring gear 69. is of: sufficientwidthto mesh with the planet gears of the lower epicyclic assembly ID; as well as. with the planet gears 18 of. the: upper assembly.- 9, so that it is. therefore common to both assemblies and provides. the fulcrumfor the torque multiplication produced by the. twostage planetary gearing of thetransrnission. The planet gears and the trunnions of these: two gear train assemblies have their axes. all in the same concentric plane with respect to the axes. of the drive and. driven shafts. The outer face ot the ring gear 6.9 fits against the cylindrical inner-surfaces of the. housing members 12-. and M5,; and it has an. outer annular flange or rib 80 that is. disposed between the proximate edges of said housing members where it is anchored by means; of the bolts N.- that secure the housing together.

The power take-off for the driven shaft 8 is accomplished. through the medium of external splines 8] on the driven shaft above the shoulder 15, which engage internal splines 32 on the inner portion of the upper carrier hub 16. A heavy ring 83 seats in an annular groove in the driven shaft and supports the upper carrier by engaging the underside of a shoulder 84 on the tapered hub 16 beneath the internal gear 82.

It will be noted that the drive and driven shafts 5 and 8 are hollow, and that the driven shaft is provided with a plurality of lateral ports, so that, when the transmission is in operation, the pump 20 will force the lubricant into the bores of these shafts for distribution through said ports to the various moving parts of the structure. A hollow plug 85 fits into the bore of driven shaft 8 and is secured in place by a pin 85 to act as a stop to arrest the upward flow of the lubricant at a level in said shaft above the upper port.

In the operation of this transmission, the rotation of drive shaft 5 is transmitted through the one-way clutch to the lower sun gear, which will actuate the lower gear train assembly in and revolve its carrier 53 at a slower speed than the drive shaft. The upper sun gear 11, which is on said carrier 53 and rotates with it, will transmit this rotative motion through the upper gear train assembly 9 (Which will be moving at a slower speed than the lower assembly ii!) to the internal gear 82 in mesh with gear 8| on the driven shaft 8, so that further or second reduction in speed is accomplished.

While I have disclosed my invention in connection with certain specific embodiments thereof it is to be understood that this is by way of illustration and not b way of limitation and the scope of my invention is defined solely by the appended claims which should be construed as broadly as the prior art will permit.

I claim:

1. A transmission gearing adapted for operation on a vertical axis, embodying; (Io-axial; drive and: driven shafts, a. planetary gear traim assembly, including a. planet gear. carrier, drivingly connecting: said shafts; auxiliary shaft independent ofi said: drive and driven shafts, a bevel gear spaced from the-carrier of said planetary gear assembly and-actuatedthereby, and a bevelipinion operatingin the space between said bevel gear and said carrier-,. said: pinion being connected to and: actuating; said: auxiliary shaft.

2.. A. transmission gearingv adapted for operation on a vertical axis, embodying: GO-aXifi'l drive and: driven shafts, a; planetary geartttain assembly, including; a planetv carrier; drivingly connecting said: shafts; an auxiliary shaft: independent of said. drive andv driiven: shafts, a. sleeve depending from: and. centered on; the carrier of said planetary gear assembly, a: bevel: gear onthe lower portion. of saidesleeve inspaced; relation to: the carrier, and a bevel: pinion. operating in the: space betweensaid bevel! gear: and-carrier, said: pinion being. connected to and actuating said auxiliary shaft.

3.. A transmission gearing adapted for operation on. a verticat axis; embodying co-axial'; drive and driven shafts; a planetary gear train assembly, including a planet gear' carrier, having drive connection with said". driven shaft; a. oneway clutch: operatively' connecting the; drive shaft to the planetary gear. assembly, an elongated sleeve depending rromathe carrierof the: planetary gear assembly and teiescoped: over said clutch, a bevel gear cn the lower portion ofv saidsleeve: in spaced. relation to the. carrier, a bevel-r pinion meshed with said bevel gear and operating in the space between said bevel gear and the carrier, and an auxiliary shaft connected to and actuated by said bevel pinion.

4. A transmission gearing for operation on a vertical axis, embodying co-axial drive and driven shafts, one of said shafts being piloted onthe other shaft, upper and lower planetary helical gear train assemblies around the driven shaft, said upper gear train including a sun gear, a shoulder on said driven shaft, and a thrust washer on the driven shaft below said shoulder, the sun gear of the upper helical gear train being disposed between said thrust Washer and shoulder to cause the end thrust of the helical teeth of the gear train to be taken on the driven shaft.

5. A transmission gearing for operation on a vertical axis, embodying co-axial drive and driven shafts, one of said shafts piloted on the other shaft, upper and lower planetary helical gear train assemblies around the driven shaft, each of said assemblies including a sun gear, the sungear of the lower helical gear train being mounted on the driven shaft and supported against longitudinal movement by the drive shaft and rotated thereby, a retainer ring engaged with the upper portion of said sun-gear, a shoulder on said driven shaft, and a thrust washer below said shoulder and maintained in position by said retainer ring, the sun-gear of the upper helical gear train being interposed between the thrust washer and said shoulder to cause the end thrust of the helical teeth of the gear train to be taken on the driven shaft.

-6. A transmission gearing for a helicopter and similar aircraft, embodying co-axial drive and driven shafts, upper and lower planetary helical gearing, including a sun gear for said lower gearing, operatively connecting said shafts to rotate the driven shaft, the sun-gear of the lower helical gearing being mounted on the driven shaft and supported against axial movement by the drive shaft and rotated thereby, a retainer-washer, a snap-ring on the driven shaft for holding the retainer-washer in engagement with said sun-gear, a shoulder on the driven shaft, a thrust-washer below said shoulder and supported by said snap-ring, and means for maintaining the retainer-washer and the thrust-washer against rotation independent of the driven shaft.

7. In a helicopter driving gear, a casing having a drive shaft bearing and a driven shaft hearing coaxial with and spaced upwardly from the drive shaft bearing, said casing also having an upwardly extending re-entrant portion about the drive shaft bearing, a drive shaft having an upper end portion within the casing and a portion extending downwardly into journalled relation with said drive shaft bearing, a driven shaft journalled in the driven shaft bearing and having a lower end portion piloted in the upper end portion of the drive shaft, said driven shaft also having a rotatable part portion disposed in the casing between the driven shaft bearing and said lower end portion, means for driving the driven shaft from the drive shaft comprising a sun gear journalled on the driven shaft bearing portion, a planet gear carrier on the driven shaft bearing portion, a ring gear fixed to said casing, planet gears journalled upon said carrier and mutually meshed with the sun and ring gears, means drivingly connecting the carrier with the driven shaft and an overrunning clutch unit disposed in driving relation between the upper end of the drive shaft and said sun gear, a steering rotor drive REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 986,588 OKelley Mar. 14, 1911 1,273,950 Teltzrow July 30, 1918 1,320,530 Beuhler Nov. 4, 1919 1,350,822 McNitt Aug. 24, 1920 1,820,061 Flagg Aug. 25, 1931 1,850,340 Cowles Mar. 22, 1932 1,882,333 Hallitt Oct. 11, 1932 1,945,361 Ball Jan. 30, 1934 1,960,141 DAsoanio May 22, 1934 1,977,943 Gianini Oct. 23, 1934 2,085,814 Matthews July 6, 1937 2,156,603 Nardone May 2, 1939 2,256,754 Schmitter Sept. 23, 1941 2,269,916 Price Jan. 13, 1942 2,271,640 I-Ieintz Feb. 3, 1942 2,318,259 Sikorsky May 1, 1943 2,333,161 Dunn Nov. 2, 1943 

